I'm developing a Flutter app on a physical android device, I don't know much about networking and I'm having a trouble using an API from the phone to a local database on my laptop.
I reviewed all the answers in this post
Cannot connect to localhost API from Android app
Nothing seems to work for me, I'm using Apache server on XAMPP, and the API works just fine from the laptop (127.0.0.1:8000/api/Students) but when I try to access it from the phone it doesn't work (I replaced 127.0.0.1 with the IP of my laptop which I took from ipconfig)
XAMPP control panel
when I try to access the server from the phone using laptop-IP:80 it access normally the same with laptop-IP:80/phpmyadmin
XAMPP dashboard
but only when my phone is connected to the laptop mobile hotspot, when I connect the two devices to the same WIFI network it shows that it's unreachable:
but when I try laptop-IP:8000/api/Students this happens:
this site can't be reached
I tried to modify Apache httpd.conf:
#Listen 12.34.56.78:80
Listen 8000 <-- Added this
from what I understood this makes the server listens to port 8000 but I'm left with the same problem
NOTE: all the pictures show my attempts to use the API on my phone's Chrome browser
You need to do some tweaks to the url to access it in the device as localhost is only known to the machine not the devices on which the app is running.
The urls are different for different devices
Emulator
Real phone (with usb debugging)
1.Emulator
static const baseUrl = "http://10.0.2.2:8000";
2.Real Device
static const baseUrl = "http://localhost:8000";
Additionally you need to run these command in your cmd,
adb reverse tcp:8000 tcp:8000
Now your requests would go like:
get('$baseUrl/api/Students');
First of, I can see on traffic coming through when I browse on my desktop.
I have set the IP in network settings along with the port but when I connect I do not get the do you want to connect this phone message from Charles.
I have:
deleted all certificates and tried to go to chls.pro/ssl but get no internet message and the certificate doesn't download.
tried ios and android both with the same result.
tried to manually add it to the access devices in Charles.
The only difference is from two weeks ago when I last did this successfully is the VPN I am on (I open the Charles before connecting to the VPN, to rule that out).
Any suggestions? I am going crazy!
There are various issues that can cause this issue: I collect here and you can verify each step to solve it: https://docs.proxyman.io/troubleshooting/my-ios-devices-couldnt-connect-to-proxyman-via-proxy
I would like to summarize:
Check if your Firewall is blocking all incoming traffic -> Turn it OFF
Stop all VPN app from your iOS device
Make sure your iOS devices and your macOS are in the same network.
Disclaimer: I create the Proxyman app, which is a modern version of Charles-Proxy. Hopefully it helps you resolve the problem.
I've been trying to capture the network traffic populated from the browser and an app hosted inside the Android emulator, using Fiddler.
I've been unsuccessful even after following the workarounds of adding proxy to the emulator (Settings - More - Cellular Networks - Access Point Names - adding the system IP and port).
You should enter this ip-address: 10.0.2.2 as a Proxy-address. You should use it cause of Android emulator haven't direct access to your local network and can't connect to local computer.
But Android Emulator has a virtual router, so you can connect to your computer by address 10.0.2.2. You can read more here
-OR-
You can use Visual Studio Android Emulator. There's using Hyper-V virtual network adapter that can connect directly to your local network
The point is you should switch air-plane mode on-off once after fill this settings in Cellular network setting / Access point Names with this settings:
Set your system IP in -> Proxy
Set fiddler port number (8888 is default) in -> Port
Clear Username and Password field.
Save and exit.
Turn-on airplane mode and then turn it off.
Now your data will capturing by Fiddler.
It just working on an old version of android.
I implemented a web service for an Android application. The web service is running on my local host (192.168.1.2). Using the Android emulator I succeeded to connect to web service. The I tried to connect my Android device using debugging mode to web service but it didn't work. So my question is if it is possible to connect an Android device to this web service that is running on my local host (192.168.1.2) without using a real IP ?
It's much simpler way supported by google!
Connect your phone via usb to computer and enable usb debugging
On your computer open Chrome browser and type exactly this address: chrome://inspect/#devices
Now you can link your computer port to your device port by port forwarding button. On my computer I have service on address localhost:61437 and I just linked it to device's 8081 port. Remeber to check 'Enable port forwarding' checkbox
screen from service on my computer ( localhost:61437 )
screen from my mobile browser with the same service ( localhost:8081). And that's it. Also you use this service address in your application
Did you already solve your problem? I also got a problem like you. These are the steps that I already done:
unplug lan cable or turn off any other internet connection from your pc.
connect your android mobile to your pc using usb.
turn on usb tethering
back to your pc. check your ip. mine is 192.168.42.37
check your webservice app in your pc. let's say http://192.168.42.37/webserviceapp
back to your android mobile. try this url http://192.168.42.37/webserviceapp
Now you can access your webservice app in your pc from your mobile phone.
Well your localhost is 127.0.0.1 (or ::1) and your LAN IP is 192.168.1.2. Each pc/device that are connected under your LAN could reach your webservice on IP 192.168.1.2
Your Android device must be so connected under the same LAN maybe through Wifi connection so it will be able to talk with 192.168.1.2.
If you can't connect your Android device under the same LAN eg you have just a 3g connection you need to play with your router/firewall to redirect all incoming traffic (maybe just the http traffic) from your public ip to you private ip (192.168.1.2)
Hope this help
I'll throw in my process, since nothing on SO worked for me. Here are the steps I took to connect my physical android device to the web service running on my laptop (connected to the phone) on localhost:
Enable USB debugging on your Android device
Run your web service on your machine. My web service runs on localhost, port 3000 in development: http://localhost:3000/api/...
Run ifconfig (Unix), or ipconfig (Windows)
Find your machine's inet address on your LAN interface. Mine is 10.0.0.121 for interface wlan0. Externally, it is 68.43.XX.XXX, which is not the address that you want to use.
Use the LAN IP since you are connecting to your service on LAN, otherwise you might get an econnrefused (connection refused) error due to firewall rules
Build your http URL with that IP address, and the port that your web service is running on. For me, it's http://10.0.0.121:3000/api/...
When you launch your app, you should connections to your local web service in logs, Wireshark, etc, and you should see the desired activity/data in your Android application.
I had the same issues, researched a lot then found out that you have to explicitly make changes in your firewall settings. Your firewall is blocking your code to be accessed from external source. So, all you need to do is, go to firewall settings, add port 80 (in my case since, I am using Apache http Server) for inbound and outbound. Now, you can test it on your phone's browser http://192.16..**:80/
I've done that on a Mac using GasMask and Charles Proxy Server. Your phone and your computer have to be on the same network.
say the webservice url you want to access is at http://api.xyz.com, you first use GasMask to point that url to your localhost, then use Charles to set up a proxy server. Then you go to the settings on your phone, go into Wi-Fi, long-press the network you are connected to, choose Modify Network, and enter the proxy settings Charles gave you.
In my case, nothing of these solutions works because Windows firewall blocks it, but putting a rule on the firewall hasn't effect.
The problem in my case is that my laptop is connected with Wifi and Windows had the Wifi connection like a Public network. I must to change the network connection to Private network. http://www.comofuncionatodo.net/tecnologia/informatica/como-cambiar-de-red-publica-a-red-privada-en-windows-10/
I agree with the other answers as good approaches if you don't want to expose your DEV webservice on the internet. However, it's much easier if you do just expose the webservice. There's a number of free DNS services, but I've found no-ip to be the easiest to set up. I use it for exactly the purpose that you asked about; so I can test with my DEV webservice on a real device.
If you choose to go with no-ip (I have no affiliation with that company, it's just the one I've used and am familiar with), you can get a free publicly accessible URL like http://MyExampleWebServer.no-ip-org, and no-ip has a utility you can install so even if you're behind a dynamic IP, it will always keep the correct external IP associated with that URL. If you're working from your house, then you'd just need to make sure you port forward traffic from port 80 to your internal 192.x.x.x IP address (or whatever port you use; maybe 443 for ssl).
It's as easy as that, and now you can hit that webservice from any device that can access the internet.
I haven't worked with it, but I believe dyndns also offers a similar service.
This solution is for GAE development server in Eclipse
Step 1: Get the LAN IP
Goto your Windows Command Console (Press Win+R, then type "cmd"). In the console, enter "ipconfig". You will see a list of display. Under Wireless LAN adapter Wi-Fi, get the IPv4 Address. It will be something 192.168.x.x
LAN IP : 192.168.x.x
Step 2:
Go to Eclipse, Open the Configured server
Under Properties of GAE Development Server -> Local Interface address to bind to, enter the LAN IP address, and save.
Step 3:
Now you can access the GAE server by
http://192.168.x.x:8888/
8888 - Refers to the Port Number, as mentioned in the GAE development server
In order to access local web services using their own server hosts rather than IP addresses with ports, do these following steps:
Make sure your Android device and your local machine are on the same network.
Install SquidMan on your Mac, Linux, or any other Proxy Server.
Configure the proxy server's HTTPPort (ex. 5555) and clients (ex. 192.168.0.0/24) to your own network mask, and run the proxy server.
You are either using the web services in:
a. A web browser: Configure the proxy settings of your Android device from Modify WiFi networks.
b. Android application:
Set up the Proxy for your HTTP client. If you are using Volley, check this out: Volley Behind a Proxy server.
You can now connect to it by using whatever URL you are using on your host to connect to the web service (ex. http://my-local-machine.com)
Hint: If you got 4xx response codes, make sure your web service allows connections from other non-local-hosts.
If you are referring your localhost on your system from the Android emulator then you have to use
http://10.0.2.2:8080/
Because Android emulator runs inside a Virtual Machine(QEMU) therefore here 127.0.0.1 or localhost will be emulator's own loopback address.
I am developing a network app for Android and I'm still stuck on connecting my real Android device with an device-emulator running on my desktop computer.
I've created private network with a router, so the only ones connected to the network are my pc and my mobile phone, in order to avoid firewall/closed ports problems.
My PC ip is 192.168.1.100 and I'm trying to ping each other so I can sea reachability of each network node. Ping works fine from my PC (not the emulator console) to the phone.
The problem is that I want to ping the PC-emulator from my mobile phone, not the PC itself... For that, I use the emulator console... Should I use my computer IP or should I use another one? I've seen some ip's like "10.0.x.x" here http://developer.android.com/guide/developing/tools/emulator.html
But I guess those are for connecting two EMULATORS, right?
Besides, I've tried to connect them by socket, creating a redirection for the port via Emulator console, but still can't connect them.
Any clues?
Thanks!!
I tried the early solution I gave you and it didn't work. As you said maybe the reason is the redir command of the emulator console only redirects packets comming from the localhost.
So I searched for a simple proxy server and used it in the same machine to test it out.
http://www.java2s.com/Code/Java/Network-Protocol/Asimpleproxyserver.htm
With this I used the following configuration:
on the proxy:
String host = "localhost";
int remoteport = 3000;
int localport = 4000;
Then run the emulator instance:
Server socket listening on port 2000.
Open telnet instance and issue "redir add tcp:3000:2000"
And finally on the real device open a socket to the machine address on port 4000.
So the network map looks like:
Device <-> machine:4000 Proxy machine:3000 <-> :3000 Emulator :2000 -> Application
This worked for me using the same application on the device and emulator.
I've reached the conclusion that emulator can only receives packets coming from the loopback (127.0.0.1), since when you issue "redir add tcp:port:newPort, it only redirects the first port (associated to the loopback) to the second port (associated to the "emulator virtual ip").
I've tried to create a bridge, which redirects all the packets coming to my pc to the IP 127.0.0.1, but still not works. Thus, I think the emulator has been developed only to communicate with other emulators...
I hope anyone that comes here contradicts me.
You may be able to connect a real device with an emulator instance.
Did you tried setting a redirection on the emulated device and then connect the real device trough a java socket?
For example:
On the emulated device open a server socket listening on port 2000, then open a telnet connection and issue the command:
redir add tcp:4000:2000
Finally, open a socket on the real device to your machine address (192.168.1.100) on port 4000.